A modern receiver is expected to reconstruct signals that are transmitted over a communication channel (also referred to as channel) from an information source (such as a transmitting antenna) to a receiving antenna of the receiver. The so-called RAKE receivers are gradually replaced by equalizer-based receivers. An equalizer is expected to adjust itself (in real time or almost in real time) to a dynamically changing channel. It is known that the complexity of an equalizer configuration process that finds an optimal or even a sub-optimal equalizer configuration is responsive to the number of non-zero taps of the equalizer.
In order to reduce the complexity (and accordingly cost) of equalizer sparse equalizers were introduced. A sparse equalizer includes a small number of non-zero taps. A sparse chip equalizer that was designed to single channel and especially for direct access code division multiple access (DS-CDMA) downlink receivers was introduced by G. Kutz and A. Chass in “Sparse chip equalizer for DS-CDMA downlink receivers”, IEEE communication letters, Vol. 9, No. 1, Jan. 2005.
The configuration process of a sparse equalizer includes selecting which taps are nonzero (this stage is also referred to selecting a timing of a nonzero tap) and then calculating the values of the non zero taps. It is noted that even this process is relatively complex and may involve evaluating only a sub set of tap allocations out of a much larger set of possible tap allocations.
Multiple input multiple output (MIMO) technology recently attracted attention in the wireless communication arena as it is expected to increase information throughput and channel range without additional bandwidth or transmit power.
It is expected that the complexity of configuring equalizers of MIMO receivers will dramatically increase and also will result in a dramatic increment of the cost of such equalizers.
There is a growing need to provide efficient methods for configuring a receiver and for efficient configurable receivers.